D
The recent, apparently successful, prediction by mathematical models of an appearance of El Nino—the warm ocean How that periodically develops along the Pacific coast of South America has excited researchers．Jacob Bjerknes pointed out years ago how winds might create either abnormally warm or abnormally cold water in the eastern equatorial （赤道附近的） Pacific．Nevertheless, before the creation of the models, no one could explain why conditions should regularly change between appearances of the warm El Nino and the so-called anti-El Nino．The answer, at least if the current model that links the behavior of the ocean to that of the atmosphere is correct, is to be found in the ocean．
It has long been known that during an El Nino, two conditions exist: unusually warm water extends along the eastern Pacific and winds blow from the west into the warmer air rising over the warm water in the east．The contribution of the model is to show that the winds of an El Nino, which raise sea level in the east, send a signal to the west lowering sea level at the same time．According to the model, that signal is created as a negative （负的） Rossby wave, a wave of lower sea level, that moves westward parallel to the equator at 25 to 85 kilometers per day．Taking months to move across the Pacific, Rossby waves march to the western boundary of the Pacific basin, which is modeled as a smootli wall but in reality consists of quite irregular island chains．
When the waves meet the western boundary, they are reflected, and the model predicts that Rossby waves will be broken into many coastal Kelvin waves carrying the same negative sea-level signal．These eventually shoot toward the equator, and then head eastward along the equator drove by the earth at a．speed of about．250 kilometers per day．When enough Kelvin waves of adequate amplitude （振幅） arrive from the western Pacific, their negative sea-level signal overcomes the feedback mechanism, raising the sea level, and they begin to drive the system into the opposite cold mode．This produces a gradual change in winds, one that will eventually send positive sea-level Rossby waves westward, waves that will eventually return as cold cycle—ending positive Kelvin waves beginning another warming cycle．
67．What is the passage mainly about?
A．How Rossby waves are found．
B．Where El Nino is formed．
C．What the models predict．
D．How the models work．
68．Where does El Nino often appear?
A．Along the western coast of the USA .
B．In the Pacific in the south, of the equator．
C．In the Pacific in the north of the equator．
D．Along the southern coast of South America．
69．What is right according to the passage?
A．Rossby waves and Kelvin waves move in opposite directions along the equator．
B．People could explain El Nino before the creation of the mathematical models．
C．Adequate sea-level waves can produce westward positive cold cycle．
D．The speed of Rossby waves is faster than that of Kelvin waves．
70．What does the underlined word "waves" in Paragraph 3 refer to?
A．Kelvin waves．       B．Sea-level signals．   C．Coastal waves．   D．Rossby waves．

D

       The recent, apparently successful, prediction by mathematical models of an appearance of El Nino—the warm ocean How that periodically develops along the Pacific coast of South America has excited researchers．Jacob Bjerknes pointed out years ago how winds might create either abnormally warm or abnormally cold water in the eastern equatorial （赤道附近的） Pacific．Nevertheless, before the creation of the models, no one could explain why conditions should regularly change between appearances of the warm El Nino and the so-called anti-El Nino．The answer, at least if the current model that links the behavior of the ocean to that of the atmosphere is correct, is to be found in the ocean．

       It has long been known that during an El Nino, two conditions exist: unusually warm water extends along the eastern Pacific and winds blow from the west into the warmer air rising over the warm water in the east．The contribution of the model is to show that the winds of an El Nino, which raise sea level in the east, send a signal to the west lowering sea level at the same time．According to the model, that signal is created as a negative （负的） Rossby wave, a wave of lower sea level, that moves westward parallel to the equator at 25 to 85 kilometers per day．Taking months to move across the Pacific, Rossby waves march to the western boundary of the Pacific basin, which is modeled as a smootli wall but in reality consists of quite irregular island chains．

       When the waves meet the western boundary, they are reflected, and the model predicts that Rossby waves will be broken into many coastal Kelvin waves carrying the same negative sea-level signal．These eventually shoot toward the equator, and then head eastward along the equator drove by the earth at a．speed of about．250 kilometers per day．When enough Kelvin waves of adequate amplitude （振幅） arrive from the western Pacific, their negative sea-level signal overcomes the feedback mechanism, raising the sea level, and they begin to drive the system into the opposite cold mode．This produces a gradual change in winds, one that will eventually send positive sea-level Rossby waves westward, waves that will eventually return as cold cycle—ending positive Kelvin waves beginning another warming cycle．

67．What is the passage mainly about?

       A．How Rossby waves are found．

       B．Where El Nino is formed．

       C．What the models predict．

       D．How the models work．

68．Where does El Nino often appear?

       A．Along the western coast of the USA .

       B．In the Pacific in the south, of the equator．

       C．In the Pacific in the north of the equator．

       D．Along the southern coast of South America．

69．What is right according to the passage?

       A．Rossby waves and Kelvin waves move in opposite directions along the equator．

       B．People could explain El Nino before the creation of the mathematical models．

       C．Adequate sea-level waves can produce westward positive cold cycle．

       D．The speed of Rossby waves is faster than that of Kelvin waves．

70．What does the underlined word "waves" in Paragraph 3 refer to?

       A．Kelvin waves．       B．Sea-level signals．   C．Coastal waves．   D．Rossby waves．

When a caterpillar （毛毛虫） feeds on a tomato leaf, the plant moves rapidly to meet with a defensive response, systematically releasing “proteinase inhibitors” – proteins that interfere （干扰） with the caterpillar’s digestion – throughout the plant, especially in the leaves. But how does the message get from the wounded leaf to the rest of the plant?

Most scientists believed the alarm was spread by chemical messengers until a team of researchers headed by David Weldon – a biologist at the University of East Anglia in Norwich, England – made a shocking discovery. An injured leaf, the researchers found, sends an electrical signal to warn neighboring leaves of upcoming danger. It’s a “terribly tiny current” driven by an electrical potential difference of only 20 millvots（瓦特）, says Weldon, who measured the voltage after electrodes were attached to the plan’s surface.

“Right now, all we can say is that there is a correlation,” Weldon notes. “If you wound the plant, you’ll see an electrical signal accompanied by a biochemical response.” To learn more about the reaction, Weldon’s team plans to insert electrodes within the plant tissue （rather than on the surface） to determine what’s going on at the cellular level. The findings may help explain other mysteries surrounding plants. For example, many plants start to flower in springtime, as days grow longer, but plants sense the change in the day length through their leaves, while flowers begin to bloom at the buds （蓓蕾）. “There must be a signal from the leaf to the growing points”, Weldon says. “So far, no one has come up with a convincing chemical mechanism. Maybe an electrical signal is involved.”

1．What is the function of the “proteinase inhibitors” in tomato plants?

       A．They create nutritional matter.

       B．They produce electrical signals.

       C．They protect the plant from insects.

       D．They cure diseases by changing chemicals.

2．The researchers discovered that          .

       A．the alarm was increased by chemical messengers

       B．the wounded leaf raised danger signals by tiny currents

       C．the whole plant was aware of the risk through different signals

       D．proteinase inhibitors expanded the warning to the plant’s surface

3．What question do scientists hope to answer with further research?

       A．Do plants send chemical messengers that register pain?

       B．Do plants create cell tissues that help rebuild the leaves?

       C．Do plants create proteinase inhibitors that warn them of danger?

       D．Do plants send electrical signals that tell them it is time to grow?

4．The best title of this passage is              .

       A．Electrical Tomatoes

       B．Endless Cycles of Plants

       C．A debatable Research

       D．A Magic Role of Caterpillars

The Green Microgym in Portland，Oregon has all the usual stuff you'd expect-sweaty people，loud music，smooth exercise equipment-but it has some extras as well. Everywhere you look，there are power wires. And these aren't the typical kind that let you surf the Web while you ride a spin cycle-although. you can do that too．The gym uses special exercise equipment that captures（捕获）the energy you create while riding, converts（转换）it into electricity and channels it into the power outlets（插座）．

The idea of using exercise equipment to produce electricity is not new. A gym in Hong Kong has been doing this since 2007. But clean (and healthy）energy is just now starting to catch on in U. S. gyms·"We have seen a significant increase in interest in the past six months，which is a good sign that fitness centers are ready to spend money on green technologies，” says Mike Curnyn，co-founder of the Green Revolution，a Connecticut-based firm that wires bikes into a central battery that can store energy.

The Green Microgym，first opened in 2008，has more than 200 members and is doing so well that owner Adam Boesel opened another one five miles from the original．Although membership costs about the same as ordinary gyms，customers can earn gift certificates from local businesses for watts produced while exercising．An average workout creates 37. 5 watt hours，which is enough to power a phone for a week．

Boesel uses spin bikes made by Resource Fitness，a Seattle company he co-owns，that captures energy produced from the flywheel. Wires send the converted AC current（交流电流） into any standard wall outlet-for this reason，the product line's name is Plug Out-and the energy created is used before the building draws power from the grid（电网）．Unlike the Green Revolution equipment，Plug Out machines cannot store extra energy. A third company，the Florida-based ReRev，is adding converters to a specific brand of spin bikes. But since the converters add＄1，000 to the price of the equipment，the ReRev and Green Revolution machines are at a disadvantage．

Resource Fitness，by contrast，sells its equipment for the same＄1，200 price as non- electricity-producing machines，removing the question of how long it will be until the energy savings pay for the cost of the unit．The company can afford to do this because its designs don’t call for the extra wiring needed for battery packs and large converters．It is also trying to price competitively with standard equipment so more gyms-and gym goers-will make the switch．

1.Members of the Green Microgym earn gift certificates for_______．

A .using the man-powered exercise equipment

B. saving electricity for local businesses

C. producing green electricity to power their phones

D. paying higher membership fees

2.The spin bikes made by Resource Fitness are different from those by Green Revolution in that_______.

A. they are easier to ride

B. they are more expensive

C. they don't have wires connected

D. they can not store extra electricity

3.What might prevent the green exercise equipment from getting more popular？

A .People's unwillingness to go green．

B. The high cost of making it.

C. Safety problems concerning electricity.

D. Lack of certificates．

4.The underlined words“make the switch”in the last paragraph most probably mean_____.

A. change to a different gym

B. use green exercise equipment

C. switch on the spin bikes

D. add a battery to the machine

        The Green Microgym in Portland，Oregon has all the usual

      stuff you'd expect-sweaty people，loud music，smooth exercise

      equipment-but it has some extras as well. Everywhere you

      look，there are power wires. And these aren't the typical kind

    that let you surf the Web while you ride a spin cycle-although

      you can do that too．The gym uses special exercise equipment

    that captures（捕获）the energy you create while riding,

    converts（转换）it into electricity and channels it into the power

    outlets（插座）．

        The idea of using exercise equipment to produce electricity is

    not new. A gym in Hong Kong has been doing this since 2007. But clean (and healthy）energy is

    just now starting to catch on in U. S. gyms·"We have seen a significant increase in interest in the

    past six months，which is a good sign that fitness centers are ready to spend money on green

    technologies，” says Mike Curnyn，co-founder of the Green Revolution，a Connecticut-based firm

    that wires bikes into a central battery that can store energy.

        The Green Microgym，first opened in 2008，has more than 200 members and is doing so well

that owner Adam Boesel opened another one five miles from the original．Although membership

costs about the same as ordinary gyms，customers can earn gift certificates from local businesses

for watts produced while exercising．An average workout creates 37. 5 watt hours，which is

enough to power a phone for a week．

        Boesel uses spin bikes made by Resource Fitness，a Seattle company he co-owns，that

captures energy produced from the flywheel. Wires send the converted AC current（交流电流）

into any standard wall outlet-for this reason，the product line's name is Plug Out-and the

energy created is used before the building draws power from the grid（电网）．Unlike the Green

Revolution equipment，Plug Out machines cannot store extra energy. A third company，the

Florida-based ReRev，is adding converters to a specific brand of spin bikes. But since the

converters add＄1，000 to the price of the equipment，the ReRev and Green Revolution machines

are at a disadvantage．

        Resource Fitness，by contrast，sells its equipment for the same＄1，200 price as non-

electricity-producing machines，removing the question of how long it will be until the energy

savings pay for the cost of the unit．The company can afford to do this because its designs don’t

call for the extra wiring needed for battery packs and large converters．It is also trying to price

competitively with standard equipment so more gyms-and gym Boers-will make the switch．

63．Members of the Green Microgym earn gift certificates for＿．

    A ．using the man-powered exercise equipment

    B. saving electricity for local businesses

  C. producing green electricity to power their phones

    D. paying higher membership fees

64．The spin bikes made by Resource Fitness are different from those by Green Revolution in that

    A. they are easier to ride B. they are more expensive

    C. they don't have wires connected D. they can not store extra electricity

65．What might prevent the green exercise equipment from getting more popular？

    A ．People's unwillingness to go green．

    B. The high cost of making it．

    C. Safety problems concerning electricity.

    D. Lack of certificates．

66. The underlined words“make the switch”in the last paragraph most probably mean

    A. change to a different gym B. use green exercise equipment

    C. switch on the spin bikes D. add a battery to the machine